Laser radar is a versatile metrology system that offers non-contact and true single-operator inspection of an object (often referred to as a target). Laser radar metrology provides high quality object inspection data that is particularly useful for numerous industries such as aerospace, alternative energy, antennae, satellites, oversized castings and other large-scale applications.
Known concepts for Laser radar systems are disclosed in U.S. Pat. Nos. 4,733,609; 4,824,251; 4,830,486; 4,969,736; 5,114,226; 7,139,446; 7,925,134; and Japanese Patent 2,664,399 which are incorporated by reference herein. The laser beam is directed from the laser radar system towards the target. The laser beam directed from the laser radar system may pass through a splitter which directs the laser beam along a measurement path and at the target, as disclosed in U.S. Pat. Nos. 4,733,609; 4,824,251; 4,830,486; 4,969,736; 5,114,226; 7,139,446; 7,925,134; and Japanese Patent 2,664,399. The laser beam directed along the measurement path is reflected back from, or scattered by, the target and a portion of that reflected or scattered laser beam is received back at the laser radar system where it is detected and processed to provide information about the target. The detection and processing of the reflected, or scattered, light is provided according to U.S. Pat. Nos. 4,733,609; 4,824,251; 4,830,486; 4,969,736; 5,114,226; 7,139,446; 7,925,134; and Japanese Patent 2,664,399; which are incorporated by reference and form no part of the present invention. The present invention is directed at the optical assembly by which a pointing beam and measurement laser beam are transmitted from the laser radar system.
An existing laser radar system has a relatively large rotating scanning (pointing) mirror that rotates relative to other parts of the laser radar system and is used to achieve beam pointing. This mirror causes system instability and polarization issues. The existing system is also not achromatic, so the two wavelengths (e.g. the pointing beam wavelength and the measurement beam wavelength) cannot be focused on a part in space simultaneously. Moreover, the existing system limits the field of view of the camera that is pointed in the same direction as the laser radar.